This project will investigate the possibility that deoxyneoguanosine residues in DNA (hypothesized to be the GC yields CG transversion pathway intermediate for heat mutagenesis in T4 bacteriophage; Bingham et al., PNAS (1976), 73:4159-4163 can indeed form a base pair with a deoxyguanosine residue on the opposing strand of a DNA double helix. Upon completion of the synthesis of deoxyneoguanosine triphosphate (dnGTP; now being carried out at the University of Illinois) the possible utilization of this compound as a substrate for in vitro DNA polymerization will be tested using T4 DNA polymerase and E. coli DNA polymerase I. If there is an indication of utilization, synthetic polymers will be made containing various natural deoxynucleoside monophosphate residues and various mole fractions of deoxyneoguanosine monophosphate residues. Synthesis will be attempted using terminal deoxynucleotidyl transferase. If these can be obtained they will be used for physiochemical studies on deoxyneoguanosine base pairing and for examination of its templating properties for in vitro DNA synthesis.